The utility model relates to a high current generator used for relay contact testing. The high current generator comprises a main circuit and a control circuit; the main circuit comprises an upflow transformer; the input terminal of an AC power supply is connected to the primary side of the upflow transformer, the secondary side is used for outputting high current used for relay contact testing, and one-way controllable silicon is serially connected to the primary side; the control circuit comprises a CPU (Central Processing Unit); and the CPU is connected with the trigger terminal of the one-way controllable silicon in a controlling manner through a controllable silicon triggering drive circuit and is connected with the input terminal of the AC power supply in a sampling manner through an AC zero crossing detecting circuit. In the high current generator, lower current is controlled by the controllable silicon on the primary side of the upflow transformer, and high current is generated on the secondary side of the upflow transformer, so that the purpose of producing high current is achieved. The controllable silicon is mounted on the primary side of the upflow transformer, and current flowing through the controllable silicon is lower, so that the requirement to current specification of the controllable silicon is lowered.